No need to dilute if adding to compost. Dilute with water at about 10:1 ratio for using on plants and trees. Female dog urine will kill grass but male will not. I think it is a hormone thing in the female urine that kills the grass.

Also - you can buy granulated Urea (46:0:0) to add a nitrogen source for compost. Cost is about $25-$30 for a 50 lb. bag but you don't need to use much since it is 46% nitrogen.